Yes, I get the SAME Illegal Instruction (yes NVTDM) AFTER installing O/S 2000 (fwd)

[Olly Betts]

On Thu, Oct 31, 2002 at 05:15:24PM +0000, Wookey wrote:
> I recall there is a problem with using the DOS version of Survex on NT as
> it prevents anything more exotic than VGA in it's video emulation.

Indeed - NT doesn't allow DOS programs to directly access hardware -
instead it emulates a VGA graphics card, and that's all DOS programs can
use.  So you're limited to 320x200 in 256 colours - that looks very
chunky on a modern PC which is probably usually running at around four
times that resolution both horizontally and vertically (so 16 times the
number of pixels).

Caverot knows this restriction, and should detect NT and force this
resolution.  Similarly for Windows 2000 (which is just NT5 renamed) and
XP (which is again really just another version of NT - so Microsoft have
now tried to sell you NT four times over) as I assume these have the same
restriction.

But the illegal instruction sounds like it's something Allegro (the
graphics library we use on DOS) is doing that's the problem.

But anyway, as Wookey says - if you've got a modern version of Windows,
you're much better off installing the Windows version rather than the
DOS version.  The DOS version is for those few people who are running
Windows 3.1, or not running windows at all.

Cheers,
    Olly